The following photo contains such a limited amount of information about Luz that at first I was not going to publish it.
I could get a rough idea of the season and the time of day, based on the direction and the length of shadows, but not the year.
However, I was intrigued by the Life logo on the photo, so I did a little digging.
Life ran as a photo based magazine from Nov 1936 when it was bought by Henry Luce. It was based in New York, and though it was aimed primarily at a US audience, it is supposed to have been read by Sir Winston Churchill. So that cut the possible date range down a bit.
A second check turned up near matching images in photo libraries. The key one is Getty Images, at http://www.gettyimages.pt/detail/fotografia-de-notícias/portuguese-men-standing-on-beach-fotografia-de-notícias/50639711?#portuguese-men-standing-on-beach-picture-id50639711 It is simply entitled Portuguese men standing on a beach.
The critical difference with the Getty Images version is that it does not have the Life logo.
Neither of the versions identify the location as Luz, nor identify the men as fishermen. That additional information appears to have been added by someone who recognised the hill shape behind, and Rocha Negra. Since the men are clearly not tourists, labelling them as fishermen seems pretty safe.
The sequence of events appears to be as follows. A photographer, Eliot Elisofon, took the photo and Getty Images acquired the rights. The Getty Images version is dated 1 Sep 1948. Then Life paid for publishing rights, added a Life logo, and put it in its weekly magazine.
Unless I get my hands on the relevant Life magazine, I cannot be certain whether any accompanying article mentions Luz, but the evidence thus far suggests not.
If that is the case, then nearly 50 years before Madeleine McCann disappeared, Luz had 60 seconds of fame in the US, even if not by name.